• 한국대기환경학회지
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• 제24권2호
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• pp.259-270
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• 2008

The regional air movement in a coastal area is generated by the different heat capacities of sea and land sides, which is called sea/land breeze. In the west coast area, the local air quality is significantly influenced by this sea/land breeze. In this study, the mathematical model is proposed to estimate the effective area of sea/land breeze. A commercial air model, that is suggested as an alternative air model by USEPA, is introduced to simulate the mechanism of sea/land breeze generation. From this study, it is confirmed that the numerical approach proposed in this study is reliable to predict the effective area of sea breeze in a coastal area. It implies that the current application of common air model needs to be carefully reviewed especially when dealing with a coastal air quality issue. It is also found that the sea breeze in Incheon area has the impact in the range of approximately 24 km in-land side, so-called penetration length.

• 유기물자원화
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• 제23권2호
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• pp.21-27
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• 2015

본 논문은 자원순환사회 구축을 목표로 필요한 재원마련을 위해 도입예정인 폐기물부담금제에 대응하기 위한 폐기물의 에너지화 제고방안을 인천시를 중심으로 평가하고 폐기물부담금제 도입을 위해 고려하여야 할 사항들을 제안하였다. 인천시의 폐기물 에너지화를 위한 주요 문제점으로 파악된 음식물 류폐기물의 반입량 감소에 따른 폐기물의 고발열량화, 종량제봉투에 혼입되어 배출되는 금속류, 건전지 등을 해결하기 위한 대책을 도출하였다.

• KIEAE Journal
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• 제8권3호
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• pp.13-18
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• 2008

Recently it is urgent issue in every department that problem from environmental disruption such as global warming. As the case of streetscape works essentially at city scenery, it is inevitable that changing from present view, which centers facilities and buildings, to environmental harmonic scenery. This study plans climate adjusting ability and improvement of thermal efficiency by putting ecological elements to buildings on a street which are essential factors of streetscape. Ultimately, this not only makes a pleasant environment but also revives being withered earth. Street-environment on eco-scape will take a part in designing sustainable city. This study acquires the way how buildings on a street get applied ecological elements as following. Roof level part : the greening surface of the rooftop(included plant box type), the greening roof as a type of pergola, the greening surface of the middle floor rooftop(included plant box type). Elevation part : climbing type, downfall type, espalier, flower bed in balcony type, wall-installing type, water wall type, other design types. Ground level part : paving the whole surface with permeability, paving the gap with permeability, plant box type, ground plant type, waterside zone, wetland, fence greening type, terrace greening type, retaining wall greening type.

• 한국입자에어로졸학회지
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• 제12권3호
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• pp.81-94
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• 2016

Managing hazardous air pollutants (HAPs) becomes an important issue with the amendment of the Clean Air Conservation Act in 2012. In this study, to develop an effective air quality management policy direction against the HAPs in Korea, (1) the HAPs control policies in the USA, United Kingdom, Japan, and the South Coast Air Quality Management District (SQAQMD) are reviewed, (2) the state of the art of the HAPs management in Korea are studied, and (3) policy directions are suggested. It was found that each country has its own policy priority and management directions. It was also found that the current HAPs management status is far behind to the countries compared in HAPs identification, emission inventory, monitoring, modeling, and risk management. Further policy directions are suggested.

• 한국물환경학회지
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• 제24권6호
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• pp.725-740
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• 2008

In this study a multi-site daily precipitation generator which generates the precipitation with similar spatial correlation, and at the same time, with conserving statistical properties of the observed data is developed. The proposed generator is intended to be a tool for down-scaling the data obtained from GCMs or RCMs into local scales. The occurrences of precipitation are simultaneously modeled in multi-sites by 2-parameter first-order Markov chain using random variables of spatially correlated while temporally independent, and then, the amount of precipitation is simulated by 3-parameter mixed exponential probability density function that resolves the issue of maintaining intermittence of precipitation field. This approach is applied to the Nakdong river basin and the observed data are daily precipitation data of 19 locations. The results show that spatial correlations of precipitation series are relatively well simulated and statistical properties of observed precipitation series are simulated properly.

• Earthquakes and Structures
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• 제18권1호
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• pp.97-111
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• 2020

Cylindrical steel tanks are important components of industrial facilities. Their safety becomes a crucial issue since any failure may cause catastrophic consequences. The aim of the paper is to show the results of comprehensive FEM numerical investigation focused on the response of cylindrical steel tanks under mining tremors and moderate earthquakes. The effects of different levels of liquid filling, the influence of non-uniform seismic excitation as well as the aspects of diagnosis of structural damage have been investigated. The results of the modal analysis indicate that the level of liquid filling is really essential in the structural analysis leading to considerable changes in the shapes of vibration modes with a substantial reduction in the natural frequencies when the level of liquid increases. The results of seismic and paraseismic analysis indicate that the filling the tank with liquid leads to the substantial increase in the structural response underground motions. It has also been observed that the peak structural response values under mining tremors and moderate earthquakes can be comparable to each other. Moreover, the consideration of spatial effects related to seismic wave propagation leads to a considerable decrease in the structural response under non-uniform seismic excitation. Finally, the analysis of damage diagnosis in steel tanks shows that different types of damage may induce changes in the free vibration modes and values of natural frequencies.

• 환경영향평가
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• 제18권6호
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• pp.377-386
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• 2009

Due to severe flooding, the long-term residence of turbidity flows within the stratified Daecheong Reservoir have lengthened. A long-term residence of turbidity flows within the stratified Daecheong Reservoir after floods has been major environmental issue. The objective of this study was to assess the impact to water supply from the hydrodynamics and turbidity outflow. Two gate operation scenarios were investigated. Scenario A refers to gate operations according to rainfall events, and scenario B refers to gate operations according to inflow. From the results of secenario A, the SS concentrations decreased from 0.44mg/l to 0.54mg/l at the front of the dam, whereas SS concentrations increased from 0.24mg/l to 1.24mg/l at the intake points at Munhi and Daejeon. From the results of scenario B, the SS concentrations decreased from 0.61mg/l to 0.83mg/l at the front of Dam; howeve, SS concentrations also decreased from 0.16mg/l to 0.48mg/l at the intake points at Munhi and Daejeon. It seems that it may be more efficient to control turbidity by creating additional outflows of generated discharge after intensive rainfalls than not.

• 상하수도학회지
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• 제29권1호
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• pp.57-63
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• 2015

Recently, Korea's municipal wastewater treatment plants generated amount of wastewater sludge per day. However, ocean dumping of sewage sludge has been prohibited since 2012 by the London dumping convention and protocol and thus removal or treatment of wastewater sludge from field sites is an important issue on the ground site. The hydrothermal carbonization is one of attractive thermo-chemical method to upgrade sewage sludge to produce solid fuel with benefit method from the use of no chemical catalytic. Hydrothermal carbonization improved that the upgrading fuel properties and increased materials and energy recovery, which is conducted at temperatures ranging from 200 to $350^{\circ}C$ with a reaction time of 30 min. Hydrothermal carbonization increased the heating value though the increase of the carbon and fixed carbon content of solid fuel due to dehydration and decarboxylation reaction. Therefore, after the hydrothermal carbonization, the H/C and O/C ratios decreased because of the chemical conversion. Energy retention efficiency suggest that the optimum temperature of hydrothermal carbonization to produce more energy-rich solid fuel is approximately $200^{\circ}C$.

• Safety and Health at Work
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• 제3권2호
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• pp.85-91
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• 2012

The occupations involved in food animal production have long been recognized to carry significant health risks for workers, with special attention to injuries. However, risk of pathogen exposure in these occupations has been less extensively considered. Pathogens are a food safety issue and are known to be present throughout the food animal production chain. Workers employed at farms and slaughterhouses are at risk of pathogen exposure and bacterial infections. The industrialization of animal farming and the use of antimicrobials in animal feed to promote growth have increased the development of antimicrobial resistance. The changed nature of these pathogens exposes workers in this industry to new strains, thus modifying the risks and health consequences for these workers. These risks are not yet recognized by any work-related health and safety agency in the world.

• Safety and Health at Work
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• 제11권1호
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• pp.103-108
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• 2020

Background: Presenteeism has emerged as an important health-related issue and has been studied in a variety of occupation groups. This study examines the relationship between emotional labor and presenteeism in nurses in Republic of Korea. Methods: As a cross-sectional study, our study was conducted on 328 female nurses participating in the fourth Korean Working Conditions Survey (2015). Nurses were identified by the Korean Industry Classification Code. Multivariable logistic regression analysis was performed to explore the association between emotional labor and presenteeism. Results: Female nurses who always or sometimes hide their emotions in the workplace were found to have a high risk for presenteeism compared with female nurses who rarely hide their emotions in the workplace {odds ratio [OR] = 2.40 [95% confidence interval (CI) 1.04-5.54]; OR = 4.12 [95% CI 1.72-9.84], respectively}. Furthermore, the risk of presenteeism was higher in nurses who sometimes engaged with complaining customers compared with nurses who rarely did so, but it lacked statistical significance. Conclusion: Presenteeism in nurses can cause various negative secondary effects; therefore, an alternative should be sought to mediate nurses' emotional labor to prevent presenteeism.